Producing high quality espresso coffee is the result of the combination of at least five factors which are so closely linked that the total result is endangered if one or more of these factors are lacking or are not of the best quality. These five factors include (1) the mixture of the coffee beans, (2) the grinding of the mixture, (3) the espresso coffee producing machine, (4) the quality of the water used, and (5) the expertise of the operator. The fifth factor in particular, the expertise of the operator, as it relates to the grinding of the whole coffee beans, the portioning of the doses of ground coffee, and the uniformity and repeatability of the ground coffee compaction, represents a large source of unnecessary potential inefficiency and quality degradation that has not been adequately addressed to date.
There are substantial limitations to current coffee grinding machines of the professional bar type that are used for the preparation and delivery of finely ground coffee for use in traditional espresso brewing. These grinding machines do not provide for each portion of coffee to be ground individually and used immediately, nor do they press the ground coffee into the portable delivery filter for the coffee machine. The majority of coffee grinding machines for bar use incorporate a manual, lever-operated, segmented holding chamber for pre-ground coffee. By pulling a lever, the operator dispenses a small quantity of ground coffee into the portable delivery filter. The operator using this system is responsible to judge when the proper amount of ground coffee has been portioned into the portable delivery filter.
Several manufacturers offer machines with a pre-ground coffee chamber for individual portioning of a preselected amount of coffee directly into the delivery filter, eliminating the operator judgment. However, these prior art portioning delivery chambers do not use the accurate and superior measuring method of volume gauging the physical quantity of the ground coffee, but rather implement the inferior measurement techniques of either portioning the coffee by controlling of the whole bean grinding time, or portioning by controlling the amount of whole coffee beans entering the grinding chamber.
There is an additional step to be performed in preparing to use ground and portioned coffee in the espresso brewing method. This step is the pressing of the ground coffee into the portable delivery filter prior to attaching the delivery filter to the espresso machine. To achieve uniformity in the pressure applied to the ground and portioned coffee, the operator performing this task uses a hand-operated pressing tool and applies a downward force to the entire surface of the ground portioned coffee as it is held in the delivery filter. This manual method has the disadvantage of requiring individual judgment as to when the correct amount of pressure has been applied. Further, this manual method of pressing ground coffee into a delivery filter by an individual operator has also been identified as one of the leading causes of repetitive injury syndrome in the coffee business today.
There are manually operated pressing tools that mount directly onto coffee grinders, but they also require operator judgment of how much pressure to apply to the ground coffee. Additionally, there are a few prior art devices that attempt to utilize automatic pressing techniques. However, these prior art devices are flawed, not only in their utilization of unsatisfactory portioning methods, but also through their implementation of inaccurate pressing techniques which do not provide for even and uniform compaction of the ground coffee at a constant rate throughout a portion. There remains a continuing need in the art for a device that grinds whole coffee beans on demand for each individual shot, accurately portions doses of ground coffee by volume quantity, and then uniformly presses the ground coffee at a constant rate throughout the portion into a standard coffee delivery filter.